...Burning Rangers isn't isometric, it's full 3D. On a console that can't handle 3D too well, so it's not much of a looker, but it's still technically impressive.
I really think it's a game that needs the HD treatment more than most. It's a good game, but it's being held back by the hardware it's on; the framerate is utterly atrocious. Could probably also do with separating the "dodge" button from the "large jump" button, since I tend to do the former when I'm trying to do the latter. (Also, I keep forgetting the game has Zelda-style jumping from platform edges, but eh, that's on me.)
I'm not sure what Saturn holy grails I have left to get, really. Shining Force III and Wisdom, I suppose. Radiant Silvergun, likely, since it's one of the few shmups I genuinely enjoy playing. Maybe Saturn Bomberman, but I live alone so it wouldn't get much use.
Beyond that, there's Duke Nukem 3D to round out the Lobotomy FPS trilogy, and Willy Wombat because it's dirt-cheap and looks kinda fun.